Remove NODE_CODE_CACHING setting

ChangeLog.md

@@ -39,6 +39,8 @@ See docs/process.md for more on how version tagging works.
 - `emscripten_clear_timeout` now releases the runtime keepalive held by the
   pending timeout, and both `emscripten_clear_timeout` and
   `emscripten_clear_immediate` are no-ops for ids that already fired. (#27720)
+- The `NODE_CODE_CACHING` setting was removed, as node's support for
+  serializing WebAssembly modules has been missing for over 5 years now.
 
 6.0.9 - 09/01/26
 ----------------

site/source/docs/compiling/CrossOriginStorage.rst

@@ -377,8 +377,6 @@ COS is a complement to, not a replacement for, existing browser caches:
 
 - **HTTP cache / Service Worker cache** — still used for per-origin caching.
   COS adds cross-origin sharing on top.
-- **``NODE_CODE_CACHING``** — a Node.js-specific V8 bytecode cache; unrelated
-  to COS.
 - **IndexedDB / OPFS** — per-origin storage; COS shares across origins.
 
 See also

site/source/docs/tools_reference/settings_reference.rst

@@ -1530,29 +1530,6 @@ also be controlled separately.
 
 Default value: false
 
-.. _node_code_caching:
-
-NODE_CODE_CACHING
-=================
-
-This saves the compiled wasm module in a file with name
-``$WASM_BINARY_NAME.$V8_VERSION.cached``
-and loads it on subsequent runs. This caches the compiled wasm code from
-v8 in node, which saves compiling on subsequent runs, making them start up
-much faster.
-The V8 version used in node is included in the cache name so that we don't
-try to load cached code from another version, which fails silently (it seems
-to load ok, but we do actually recompile).
-
-- The only version known to work for sure is node 12.9.1, as this has
-  regressed, see
-  https://github.com/nodejs/node/issues/18265#issuecomment-622971547
-- The default location of the .cached files is alongside the wasm binary,
-  as mentioned earlier. If that is in a read-only directory, you may need
-  to place them elsewhere. You can use the locateFile() hook to do so.
-
-Default value: false
-
 .. _exported_functions:
 
 EXPORTED_FUNCTIONS
@@ -3630,3 +3607,4 @@ for backwards compatibility with older versions:
  - ``DETERMINISTIC``: No longer supported (Valid values: [0])
  - ``LEGALIZE_JS_FFI``: legacy JS FFI legalization is no longer supported (Valid values: [0])
  - ``SOCKET_WEBRTC``: No longer supported (Valid values: [0])
+ - ``NODE_CODE_CACHING``: No longer supported (Valid values: [0])

src/preamble.js

@@ -545,40 +545,8 @@ var splitModuleProxyHandler = {
 
 #if SPLIT_MODULE || !WASM_ASYNC_COMPILATION
 function instantiateSync(file, info) {
-  var module;
   var binary = getBinarySync(file);
-#if NODE_CODE_CACHING
-  if (ENVIRONMENT_IS_NODE) {
-    var v8 = require('node:v8');
-    // Include the V8 version in the cache name, so that we don't try to
-    // load cached code from another version, which fails silently (it seems
-    // to load ok, but we do actually recompile the binary every time).
-    var cachedCodeFile = '{{{ WASM_BINARY_FILE }}}.' + v8.cachedDataVersionTag() + '.cached';
-    cachedCodeFile = locateFile(cachedCodeFile);
-    var hasCached = fs.existsSync(cachedCodeFile);
-    if (hasCached) {
-#if RUNTIME_DEBUG
-      dbg('NODE_CODE_CACHING: loading module');
-#endif
-      try {
-        module = v8.deserialize(fs.readFileSync(cachedCodeFile));
-      } catch (e) {
-        err(`NODE_CODE_CACHING: failed to deserialize, bad cache file? (${cachedCodeFile})`);
-        // Save the new compiled code when we have it.
-        hasCached = false;
-      }
-    }
-  }
-  module ||= new WebAssembly.Module(binary);
-  if (ENVIRONMENT_IS_NODE && !hasCached) {
-#if RUNTIME_DEBUG
-    dbg('NODE_CODE_CACHING: saving module');
-#endif
-    fs.writeFileSync(cachedCodeFile, v8.serialize(module));
-  }
-#else // NODE_CODE_CACHING
-  module = new WebAssembly.Module(binary);
-#endif // NODE_CODE_CACHING
+  var module = new WebAssembly.Module(binary);
   var instance = new WebAssembly.Instance(module, info);
   return [instance, module];
 }

src/settings.js

@@ -1060,25 +1060,6 @@ var NODERAWFS = false;
 // also be controlled separately.
 var NODE_HOST_ENV = false;
 
-// This saves the compiled wasm module in a file with name
-// ``$WASM_BINARY_NAME.$V8_VERSION.cached``
-// and loads it on subsequent runs. This caches the compiled wasm code from
-// v8 in node, which saves compiling on subsequent runs, making them start up
-// much faster.
-// The V8 version used in node is included in the cache name so that we don't
-// try to load cached code from another version, which fails silently (it seems
-// to load ok, but we do actually recompile).
-//
-// - The only version known to work for sure is node 12.9.1, as this has
-//   regressed, see
-//   https://github.com/nodejs/node/issues/18265#issuecomment-622971547
-// - The default location of the .cached files is alongside the wasm binary,
-//   as mentioned earlier. If that is in a read-only directory, you may need
-//   to place them elsewhere. You can use the locateFile() hook to do so.
-//
-// [link]
-var NODE_CODE_CACHING = false;
-
 // Symbols that are explicitly exported. These symbols are kept alive through
 // LLVM dead code elimination, and also made accessible outside of the
 // generated code even after running closure compiler (on "Module").  Native

test/test_other.py

@@ -9777,41 +9777,6 @@ def test_getpass(self):
     self.assertEqual(returncode, 0)
     self.assertIn(b'done', output)
 
-  @disabled('https://github.com/nodejs/node/issues/18265')
-  def test_node_code_caching(self):
-    self.run_process([EMCC, test_file('hello_world.c'),
-                      '-sNODE_CODE_CACHING',
-                      '-sWASM_ASYNC_COMPILATION=0'])
-
-    def get_cached():
-      cached = glob.glob('a.out.wasm.*.cached')
-      if not cached:
-        return None
-      self.assertEqual(len(cached), 1)
-      return cached[0]
-
-    # running the program makes it cache the code
-    self.assertFalse(get_cached())
-    self.assertEqual('Hello, world!', self.run_js('a.out.js').strip())
-    self.assertTrue(get_cached(), 'should be a cache file')
-
-    # hard to test it actually uses it to speed itself up, but test that it
-    # does try to deserialize it at least
-    create_file(get_cached(), 'waka waka')
-    ERROR = 'NODE_CODE_CACHING: failed to deserialize, bad cache file?'
-    self.assertContained(ERROR, self.run_js('a.out.js'))
-    # we cached proper code after showing that error
-    self.assertEqual(read_binary(get_cached()).count(b'waka'), 0)
-    self.assertNotContained(ERROR, self.run_js('a.out.js'))
-
-  def test_node_code_caching_incompatible_settings(self):
-    self.assert_fail([EMCC, test_file('hello_world.c'), '-sNODE_CODE_CACHING', '-sWASM_ASYNC_COMPILATION=0', '-sSINGLE_FILE'],
-                     'emcc: error: NODE_CODE_CACHING is not compatible with SINGLE_FILE (saves a file on the side)')
-    self.assert_fail([EMCC, test_file('hello_world.c'), '-sNODE_CODE_CACHING'],
-                     'emcc: error: NODE_CODE_CACHING is not compatible with WASM_ASYNC_COMPILATION')
-    err = self.run_process([EMCC, test_file('hello_world.c'), '-sNODE_CODE_CACHING', '-sWASM_ASYNC_COMPILATION=0', '-sENVIRONMENT=web'], stderr=PIPE).stderr
-    self.assertContained('warning: NODE_CODE_CACHING ignored since `node` not in `ENVIRONMENT` [-Wunused-command-line-argument]', err)
-
   @with_env_modify({'LC_ALL': 'C'})
   def test_autotools_shared_check(self):
     expected = ': supported targets:.* elf'

tools/link.py

@@ -1803,8 +1803,6 @@ def get_full_import_name(name):
       diagnostics.warning('unused-command-line-argument', 'NODERAWFS ignored since `node` not in `ENVIRONMENT`')
     if settings.NODERAWSOCKETS:
       diagnostics.warning('unused-command-line-argument', 'NODERAWSOCKETS ignored since `node` not in `ENVIRONMENT`')
-    if settings.NODE_CODE_CACHING:
-      diagnostics.warning('unused-command-line-argument', 'NODE_CODE_CACHING ignored since `node` not in `ENVIRONMENT`')
 
   settings.PRE_JS_FILES = options.pre_js
   settings.POST_JS_FILES = options.post_js

tools/settings.py

@@ -167,8 +167,6 @@
   ('WASM_ESM_INTEGRATION', 'WASM2JS', None),
   ('WASM_ESM_INTEGRATION', 'ABORT_ON_WASM_EXCEPTIONS', None),
   ('FORCE_FILESYSTEM', 'NO_FILESYSTEM', None),
-  ('NODE_CODE_CACHING', 'SINGLE_FILE', 'saves a file on the side'),
-  ('NODE_CODE_CACHING', 'WASM_ASYNC_COMPILATION', None),
 ]
 
 EXPERIMENTAL_SETTINGS = {
@@ -279,6 +277,7 @@
   ['DETERMINISTIC', [0], 'No longer supported'],
   ['LEGALIZE_JS_FFI', [0], 'legacy JS FFI legalization is no longer supported'],
   ['SOCKET_WEBRTC', [0], 'No longer supported'],
+  ['NODE_CODE_CACHING', [0], 'No longer supported'],
 ]
 
 user_settings: dict[str, str] = {}